Gate driving apparatus for power semiconductor device

Abstract

A gate driving apparatus for a power semiconductor device may include: a first off-resistor and a second off-resistor each having a first end connected to a gate of the power semiconductor device; a first off-switch configured to determine a connection state between a second end of the first off-resistor and a ground based on a gate driving signal for determining an on/off state of the power semiconductor device; a second off-switch configured to determine a connection state between a second end of the second off-resistor and the ground; an electric current detector configured to detect an electric current flowing from a collector (drain) of the power semiconductor device to an emitter (source) of the power semiconductor device; and a controller configured to determine an open/closed state of the second off-switch based on the gate driving signal and a magnitude of the electric current detected by the electric current detector.

What is claimed is: 
     
       1. A gate driving apparatus for a power semiconductor device, the apparatus comprising:
 a first off-resistor and a second off-resistor each having a first end connected to a gate of the power semiconductor device; 
 a first off-switch configured to determine a connection state between a second end of the first off-resistor and a ground based on a gate driving signal for determining an on/off state of the power semiconductor device; 
 a second off-switch configured to determine a connection state between a second end of the second off-resistor and the ground; 
 an electric current detector configured to detect an electric current flowing from a collector (drain) of the power semiconductor device to an emitter (source) of the power semiconductor device; and 
 a controller configured to determine an open/closed state of the second off-switch based on the gate driving signal and a magnitude of the electric current detected by the electric current detector, 
 wherein the electric current detector is configured to detect a voltage between the collector (drain) of the power semiconductor device and the emitter (source) of the power semiconductor device based on a predetermined current and voltage characteristics between the collector (drain) of the power semiconductor device and the emitter (source) of the power semiconductor device, and to determine whether the electric current flowing from the collector (drain) of the power semiconductor device to the emitter (source) of the power semiconductor device is between a preset first level and a preset second level higher than the preset first level, 
 wherein the electric current detector includes:
 a first comparator configured to compare a first reference voltage corresponding to the present first level with the voltage between the collector (drain) of the power semiconductor device and the emitter (source) of the power semiconductor device; and 
 a second comparator configured to compare a second reference voltage corresponding to the preset second level with the voltage between the collector (drain) of the power semiconductor device and the emitter (source) of the power semiconductor device 
 
 wherein the first comparator is a non-inverting comparator having an inverting input terminal to which the first reference voltage is input and a non-inverting input terminal to which the voltage between the collector (drain) of the power semiconductor device and the emitter (source) of the power semiconductor device is input, and 
 wherein the second comparator is an inverting comparator having a non-inverting input terminal to which the second reference voltage is input and an inverting input terminal to which the voltage between the collector (drain) of the power semiconductor device and the emitter (source) of the power semiconductor device is input. 
 
     
     
       2. The apparatus of  claim 1 , further comprising:
 a gate driver configured to output the gate driving signal; 
 an on-switch that is closed within a high-level-section of the gate driving signal and is open within an off-section of the gate driving signal; and 
 an on-resistor connected between the on-switch and the gate of the power semiconductor device, 
 wherein, when the on-switch is closed, a power source voltage is applied to the gate of the power semiconductor device through the on-resistor. 
 
     
     
       3. The apparatus of  claim 1 , wherein the first off-switch is open within a high-level-section of the gate driving signal and is closed within a low-level-section of the gate driving signal. 
     
     
       4. The apparatus of  claim 3 , wherein, when the magnitude of the electric current detected by the electric current detector is between a preset first level and a preset second level higher than the first level, and the gate driving signal is a low-level signal, the controller allows the second off-switch to be closed. 
     
     
       5. The apparatus of  claim 1 , wherein the electric current detector further includes:
 a diode having a cathode that is connected to the collector (drain) of the power semiconductor device; and 
 a capacitor connected between the emitter (source) of the power semiconductor device and an anode of the diode, 
 wherein connecting nodes between the diode and the capacitor are connected to an input terminal of the first comparator and to an input terminal of the second comparator, respectively. 
 
     
     
       6. The apparatus of  claim 4 , further comprising:
 a protection circuit configured to determine whether an excessive voltage is applied to the collector (drain) of the power semiconductor device. 
 
     
     
       7. The apparatus of  claim 6 , wherein the protection circuit includes:
 a plurality of voltage dividing resistors configured to divide a power source voltage that applies a voltage to the collector (drain) of the power semiconductor device; and 
 a comparator configured to compare the voltage divided by the plurality of voltage dividing resistors with a reference voltage corresponding to a preset third level higher than the preset second level. 
 
     
     
       8. A gate driving apparatus for a power semiconductor device, the apparatus comprising:
 a gate driver configured to output a gate driving signal that determines whether the power semiconductor device is on or off; 
 a first off-switch that is open within a high-level-section of the gate driving signal and is closed within a low-level-section of the gate driving signal; 
 a first off-resistor connected between the first off-switch and a gate of the power semiconductor device; 
 a second off-switch that is open within the high-level-section of the gate driving signal and is closed when a magnitude of an electric current flowing from a collector (drain) of the power semiconductor device to an emitter (a source) of the power semiconductor device is between a preset first level and a preset second level higher than the preset first level, and the gate driving signal is within the low-level-section; 
 a second off-resistor connected between the second off-switch and the gate of the power semiconductor device; and 
 a protection circuit configured to determine whether an excessive voltage is applied to the collector (drain) of the power semiconductor device, 
 wherein, when the first off-switch or the second off-switch is closed, the first off-resistor or the second off-resistor is connected to a ground, and 
 wherein the protection circuit includes: 
 a plurality of voltage dividing resistors configured to divide a power source voltage that applies a voltage to the collector (drain) of the power semiconductor device; and 
 a comparator configured to compare the voltage divided by the plurality of voltage dividing resistors with a reference voltage corresponding to a preset third level higher than the preset second level. 
 
     
     
       9. The apparatus of  claim 8 , further comprising:
 an electric current detector configured to detect the electric current flowing from the collector (drain) of the power semiconductor device to the emitter (source) of the power semiconductor device and to determine whether the detected electric current is between the preset first level and the preset second level; and 
 a controller configured to determine an open/closed state of the second off-switch based on whether the detected electric current is between the preset first level and the preset second level and whether a level of the gate driving signal is high or low. 
 
     
     
       10. The apparatus of  claim 9 , wherein the electric current detector includes:
 a first comparator configured to compare a first reference voltage corresponding to the preset first level determined based on a predetermined electric current and voltage characteristics between the collector (drain) of the power semiconductor device and the emitter (source) of the power semiconductor device with a voltage between the collector (drain) of the power semiconductor device and the emitter (source) of the power semiconductor device; and 
 a second comparator configured to compare a second reference voltage corresponding to the preset second level determined based on the predetermined electric current and voltage characteristics between the collector (drain) of the power semiconductor device and the emitter (source) of the power semiconductor device with the voltage between the collector (drain) of the power semiconductor device and the emitter (source) of the power semiconductor device. 
 
     
     
       11. The apparatus of  claim 10 , wherein the first comparator is a non-inverting comparator having an inverting input terminal to which the first reference voltage is input and a non-inverting input terminal to which the voltage between the collector (drain) of the power semiconductor device and the emitter (source) of the power semiconductor device is input, and
 the second comparator is an inverting comparator having a non-inverting input terminal to which the second reference voltage is input and an inverting input terminal to which the voltage between the collector (drain) of the power semiconductor device and the emitter (source) of the power semiconductor device is input. 
 
     
     
       12. The apparatus of  claim 10 , wherein the electric current detector further includes;
 a diode having a cathode that is connected to the collector (drain) of the power semiconductor device; and 
 a capacitor connected between the emitter (source) of the power semiconductor device and an anode of the diode, 
 wherein connecting nodes between the diode and the capacitor are connected to an input terminal of the first comparator and to an input terminal of the second comparator, respectively.